During the growth in popularity of decorative emblems on garments such as T-shirts or jackets, there has been a continuing desire for ways to make such emblems retroreflective. On an outer garment worn at night, such retroreflective emblems would provide a bright return of light to oncoming motorists, thereby adding a safety feature, as well as increased decorative appeal, to the garments.
Insofar as known, no one has previously found a practical or commercially useful way to provide such retroreflective emblems. Some have proposed silk-screening a design onto a garment, and then while the design is still wet, cascading microspheres onto the design; but such an approach is messy, usually provides nonuniform deposit of microspheres, and is impractical for obtaining high reflective brightness (which requires that the embedded surfaces of the microspheres be covered with a specularly reflective layer). Others have proposed mixing hemispherically specularly-coated glass microspheres into ink and printing such an ink onto the garment (see Longlet et al, U.S. Pat. No. 3,535,019); but while such a product is useful for some purposes, it provides a reduced reflectance because the hemispherically-coated microspheres are randomly oriented within an applied coating. Still others long ago proposed the preparation of retroreflective decals comprising a layer of glass microspheres disposed over a printed design (see Phillippi, U.S. Pat. No. 2,422,256); but the suggested decal was a several-layer product almost certainly stiff and unsuited for conformable garments; and the reflective area of the decal was not coextensive with the design areas, with the result that formation of a reflective emblem required a separate cutting operation in registration with the design incorporated in the decal.
The only commercial products suitable for reflective emblems or markings on garments have generally been single-colored tapes or sheet materials, with constructions as described in Palmquist et al, U.S. Pat. No. 2,567,233; Bingham et al., U.S. Pat. No. 3,551,025; Bingham, U.S. Pat. No. 3,700,305; and Bingham, U.S. Pat. No. 3,758,192. But none of these commercial products is useful to form the complex multi-colored designs that are in fashion and are needed to maximize use of retroreflective emblems.
The result is that, in spite of the described efforts, multi-colored designs or emblems on garments continue to be non-retroreflective and the potential use of such emblems for safety purposes goes unrealized.